Vehicles, such as hybrid vehicles, plug-in hybrid vehicles, and electric vehicles, are mounted with a power-drive high-voltage rechargeable battery, an inverter that converts the power of the direct-current high-voltage output of the high-voltage rechargeable battery into the power of alternating current high voltage output for driving a motor, and other devices. The inverter includes a power module having a built-in power semiconductor chip.
As a power module, a structure is known in which a semiconductor chip is mounted between a pair of conductor plates thermally coupled to a heat dissipation plate. Moreover, a power module is known, which also uses a conductor plate as a heat dissipation plate. The semiconductor chip has one face and another face opposite to the one face. The one face and the another face of the semiconductor chip are respectively soldered to one or the other of a pair of conductor plates with the semiconductor chip sandwiched between the pair of conductor plates. In order to achieve high packaging density, a plurality of semiconductor chips is sometimes mounted between a pair of conductor plates. The area around the semiconductor chip is sometimes filled with a sealing resin (see e.g. Patent Literature 1).